1. Field of the Invention
The invention concerns a device for introducing a foreign material into the ground or for compacting the ground with a depth vibrator as the primary tool.
2. Description of the Related Art
In work involving a deep vibrator, one employs at the present time the xe2x80x9cfree riding methodxe2x80x9d, that is, the vibrator is attached to a strip shovel or cable excavator or the like cable lift device via a cable pulley or a hook or the Maekler guide (framework or rigging).
Besides this, three or more part carrier mechanisms (arms or booms) are known from pile drivers (Dectilepile, FIG. 4.16, construction handbook, 4th edition, page 64, Ernst and Sohn publishers). However, these have until now not been used in combination with deep vibrators.
The Maekler (framework or rigging) guide has, in contrast to the free riding method, the advantage of the limitation of the degree of freedom or displaceability of the vibrating unit to a pre-determined preferably vertical line, so that foreign objects (for example, piles, gravel, columns, drains) can be constructed with the desired verticality. Objects with a pre-determined tilt out of the vertical can absolutely not be constructed with the free riding system.
Particularly in the production of vibration cement piles or gravel vibration columns (so called vibration stamping compacting) the problem has however occurred with the conventional Maekler guide, that the lower stop point of the guide cannot be used or can only rarely be used, since the tortional forces occurring due to the unidirectional insertion or setting into the ground during the sinking process in combination with the also occurring vibrations have led to unacceptable damage in the work and carrier mechanisms. By using only the upper stop point of the Maekler, a so called vibration bead or track, there is in practice intentionally all necessary degrees of freedom of deflection from the vertical penetration direction permitted during the entry or penetration by the vibrator, in order to avoid damage to the device. As a result, the criteria of verticality of the material columns in the ground is however at least partially compromised.
In the likewise conventional method of lowering self-sinking work devices into the ground, such as for example deep vibrators, free-hanging from a cable pulley or similar device, a manual follow-up guiding or resetting is perhaps possible, however, due to the free or loose cable guide this is not definable and cannot be automated.
The Maekler guide makes it possible to apply pull devices not only in the upwards direction, but rather, with the aid of a vertical capstan guide to have a double acting cable acting on the Maekler sled, and so to exercise pull forces downwards on the vibrator. These forces, acting in addition to the weight, significantly supplement the penetration of the vibrator into the ground and substantially accelerate the work progress, or in certain cases, make it possible for the first time to achieve the desired depth.
The free riding method has the advantage, that the high freedom of movement of the vibrating unit on the cable makes possible a very rapid movement between the work points, since in comparison to the Maekler device, it is necessary only to pivot the boom, not however to move the entire device.
Working in the water from embankments or from pontoons, the free riding method is economically superior to the Maekler method, since supplementary rigging and special constructions can be dispensed with. Also, in the case of soft construction ground having insufficient carrying capacity for the heavier tractor or caterpillar of the Maekler vehicle (usually a type of pile driver), the free riding method is advantageous, or employment of the Maekler guide may not even be possible. Frequently, the ground or soil particularly in the vicinity of the vibration point is softened, and the load-bearing capacity is reduced.
This is precisely the point of the greatest application of force of the carrier or tractor of the Maekler.
As rental devices the earth construction machines using the free riding methods (primarily cable pulleys, or as the case may be auto cranes) are more economical and easier to obtain than in the case of the special rigging required for the Maekler method.
As the state of the art, further reference is made to the following publications:
DE 22 60 473 C3 describes a device for producing material columns in the ground, in which a deep vibrator is provided on a cantilever beam of a lifting device via a rod.
For compacting the ground, a device is known from U.S. Pat. No. 4,280,770, in which a tube or pipe-like vibration unit on its upper end is connected to a boom of a dredge or excavating machine, and is applied to the ground via the boom. By vibration of the vibration unit, this sinks into the ground with compacting of the soil and is subsequently withdrawn and moved to the next position. In contrast to deep vibration, no change in direction of the vibration unit along a pre-determined direction is necessary, thus the corresponding means therefore are not provided.
From DE-GM 72 27 703 a trench compactor is known with a submersible or penetrating vibrator provided on the lower end of a rod or beam. The rod is provided on a boom of a hydraulic dredge, which urges the vibrator at a target point into the ground. The submersible vibrator remains stationary in the ground during the compacting process and after conclusion of the compacting process is again withdrawn from the ground. In comparison to deep vibrators, a moveability of the submersible vibrators plays no role, and thus means therefore are not provided.
It is the task of the present invention to provide a device for introduction of a foreign substance into the ground and/or for compacting the ground, which does not exhibit the above-mentioned disadvantages.
In accordance therewith, the device includes a penetrating unit including a deep vibrator which is coupled to an articulated arm or boom, wherein a control device is provided, by means of which the articulated arm or boom is controllable in such a manner, that the penetrating unit is guidable linearly in a predetermined direction along its longitudinal direction.
The provision of the penetrating unit on the articulated arms makes possible, in comparison to the devices based on the free riding method, the desired limitation of the degree of freedom during a movement of the penetrating unit. On the other hand, the provision of the penetrating unit on the articulated arms makes possible more freedom of movement in so far as it is desired that the penetrating unit, taking advantage of the moveability of the articulated arms, can be applied to various adjacent entry points in the ground without the need to move the earth construction machine carrying the articulated arm, as has been necessary in the case of devices which function in accordance with the Maekler method.
A linear introduction of the penetrating unit into the ground perpendicularly or at any almost freely selectable angle is made possible by a control unit. The arm is controlled by the control unit in such a manner, that the penetration unit in its longitudinal direction can be introduced linearly into the ground for production of a material column, without producing any transverse forces between the penetrating unit and the wall of the opening which already exists, or which is produced by the introduction of the penetrating unit, during the introduction or the pulling out of the penetrating unit.